• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5260-5266
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• 2015

To develop weapon system, Concurrent Spare Parts(CSP) is one of the important somethings in terms of Intergrated Logistics System(ILS). CSP is very important to improve the availability of weapon system, and various research about CSP are performed. However, most of the research does not consider the effects between sub-item's failure and weapon system's multiple function. In other words, if sub-item's failure does not seriously influence weapon system's specific function, the point, not necessarily to replace sub-item, is not considered. Therefore, the method to calculate CSP based on above consideration is written by failure-function matrix in this paper. The study follows the procedure below. First, it's to define the operation and maintenance procedure of weapon system. Second, failure-function matrix is developed. Third, simulation model is desinged by input data. Finally, The quantity of CSP is calculated by simulation and evolution strategy, meta-model. This study suggests new research direction to calculate CSP.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.2
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• pp.109-117
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• 2021

Purpose : This study examined the differences in occupational therapists' jobs depending on their past clinical careers using a survey of the importance of occupational therapy tasks in South Korea. This survey sought to provide fundamental data for strengthening occupational therapists' capacities and developing clinical training programs for therapists' future careers. Methods : An online survey was used to collect data from 93 South Korean occupational therapists. The subjects were divided into three groups for the analysis of the importance of occupational therapy tasks, depending on the length of their clinical careers: less than 3 years, from 4 to 6 years, and over 7 years. Results : A within-groups comparison of task importance found that "occupational therapy evaluation" was most important in all three groups. In between-groups comparisons, "patient information check", "assessment planning and establishment", "sensory function assessment", "social skills assessment", "developmental function improvement", "basic daily activities training", "social skills improvement", and "patient education" demonstrated statistically significant differences (p<.05). Each group showed different priorities. In the less-than-3-years group, "understanding of patient's needs" was most important, followed by "arm function improvement", "arm function assessment", "nerve, musculoskeletal, and motor-related functional improvement", and "basic daily activities training". In the 4-to-6-years group, "arm function assessment" was most important, followed by "basic daily activities assessment", "patient's needs", "arm function improvement", and "patient information check". In the over-7-years group, "understanding of patient's needs" was most important, followed by "patient information check", "basic daily activities assessment", "basic daily activities training", and "sensory function assessment". Conclusion : This study found that what occupational therapists consider important in their jobs varies according to their past clinical career and that occupational therapists with more than 7 years' experience are more aware of the importance of diverse fields of occupational therapy. Differentiated education that considers length of career and a range of training programs for more experienced occupational therapists will be needed in the future.

• Communications of the Korean Mathematical Society
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• v.31 no.2
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• pp.329-342
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• 2016

Motivated essentially by Brychkov's work [1], we evaluate some new integrals involving hypergeometric function and the logarithmic function (including those obtained by Brychkov[1], Choi and Rathie [3]), which are expressed explicitly in terms of Gamma, Psi and Hurwitz zeta functions suitable for numerical computations.

• Communications of the Korean Mathematical Society
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• v.36 no.2
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• pp.277-298
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• 2021

In this paper, we propose an extension of the classical Bessel function by means of our ℓ-hypergeometric function [2]. As the main results, the infinite order differential equation, the generating function relation, and contour integral representations including Schläfli's integral analogue are derived. With the aid of these, other results including some inequalities are also obtained. At the end, the graphs of these functions are plotted using the Maple software.

• Honam Mathematical Journal
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• v.37 no.1
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• pp.113-126
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• 2015

Recently, Liu and Wang generalized Appell's and Lauricella's hypergeometric functions. Motivated by the work of Liu and Wang, the main object of this paper is to present new generalizations of Appell's and Lauricella's hypergeometric functions. Some integral representations, transformation formulae, differential formulae and recurrence relations are obtained for these new generalized Appell's and Lauricella's functions.

• Journal of the Korean Statistical Society
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• v.25 no.1
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• pp.111-122
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• 1996

A model for a system whose state changes continuously with time is introduced. It is assumed that the system is modeled by a Brownian motion with negative drift and an absorbing barrier at the origin. A repairman arrives according to a Poisson process and repairs the system according to an (s,S) policy, i.e., he increases the state of the system up to S if and only if the state is below s. A partial differential equation is derived for the distribution function of X(t), the state of the system at time t, and the Laplace-Stieltjes transform of the distribution function is obtained by solving the partial differential equation. For the stationary case the explicit expression is deduced for the distribution function of the stationary state of the system.

• The Pure and Applied Mathematics
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• v.12 no.3 s.29
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• pp.223-228
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• 2005

In 2001, Choi, Harsh & Rathie [Some summation formulas for the Appell's function $F_1$. East Asian Math. J. 17 (2001), 233-237] have obtained 11 results for the Appell's function $F_1$ with the help of Gauss's summation theorem and generalized Kummer's summation theorem. We aim at presenting 22 more results for $F_1$ with the help of the generalized Gauss's second summation theorem and generalized Bailey's theorem obtained by Lavoie, Grondin & Rathie [Generalizations of Whipple's theorem on the sum of a $_3F_2$. J. Comput. Appl. Math. 72 (1996), 293-300]. Two interesting (presumably) new special cases of our results for $F_1$ are also explicitly pointed out.

• The Korean Journal of Community Living Science
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• v.24 no.3
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• pp.289-300
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• 2013

The aims of this study are to investigate the differences of the preschoolers' executive function and verbal ability according to their age, and to identify whether the preschoolers' executive function is related to their verbal ability. The participants in this study are 151 children, ages 3-and 5-years old from five child-care centers located in a middle-income region of Seoul. Statistical methods used for the data analysis are the frequencies, means, standard deviations, an independent t-test, and Pearson correlation. The major findings are as follows. First, an age difference is found for children's executive function. The 5-year-olds are more likely to succeed on tasks of executive function than the 3-year-olds. Also, age difference is found for children's verbal ability. The 5-year-olds perform better on tests of verbal ability than the 3-year-olds. Last, the 3-year-olds' and 5-year-olds' executive function is related to their verbal ability. Inhibition and cognitive flexibility are significantly correlated with verbal ability. These results suggest that preschoolers' executive function and verbal ability develop during preschool age. These results also suggest that preschoolers' executive function is related to their verbal ability.

• Korean Journal of Social Welfare
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• v.40
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• pp.5-37
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• 2000

The purpose of this study is to find out some characteristics of the family functions of single mothers to provide some useful data for the development of programs which may help single mothers to improve their family functions. The McMaster Family Assessment Device (FAD) which is composed of problem solving function (PS), communication function (CF), role function (RC), emotional reaction function (ER), emotional involvement (EI), behavioral control function (BC), and general function (GC) and McCubbins' FSI were administered to single mothers and their adolescent children and mothers and their adolescent children of ordinary families (control family). The single mothers' perception of their family function was lower than that of control family mothers in an the 7 categories of FAD. The perceptions of the family function of the single mothers' children were lower than those of control family mothers' children. There was on significant difference between the perceptions of single mothers and their children in PS, ER, EI, GC of their family. However, single mothers' perception in RC and BC was lower than that of their children, and the children's perception in CF were lower than that of their mothers. Single mothers who fall on the period of single motherhood was shorter than 7 years perceived their families' function as lower than that of single mothers' who fall on the periods of single motherhood longer than 7 years in all categories. Generally speaking, the single mothers' family functions were lower than that of control family. The different characteristics of each single mother's family functions should be considered in developing programs for single mothers.

• Journal of Preventive Medicine and Public Health
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• v.24 no.3 s.35
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• pp.400-413
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• 1991

The purpose of this paper is to identify factors affecting the optimum mix of required inputs and other relevant factors which account for the variation in physician's productivity in general hospitals, and to find out their implications for the efficient health planning and management. An extended version of Cobb-Douglas production function and cross sectional data of one day patient census from all general hospitals in Korea in 1988 were used in the analysis. Main results of the analysis and their implications could be summarized as follows : (1) The production function for physician's inpatient service shows the evidence of economies of scale, but the production function for physician's outpatient and adjusted-patient service, which combines both out- and in-patient service, shows that of dis-economies of scale. (2) The physician's role for production for all service is smaller than auxiliary personnel's, which imply that more intensive utilization of nurses, nursing aides and other auxiliary personnel is desirable for improving general hospital productivity (3) In case of physician's inpatient and adjusted-patient service, nurses' role is greater than nursing aides'. Therefore, more extensive utilization of nurses is recommended for the efficient operation of general hospitals. (4) The factor of hospital beds plays the leading role among required inputs in the production for physician's in- and adjusted-patient service. (5) The physician's productivity of general hospitals in rural area is lower than that in urban area. And the productivity of teaching hospitals is lower than that of the other hospitals. Further analysis was made in physician production function based upon the size of hospitals, namely those hospitals below 250 beds and those above. Explained variances by the factor of hospital beds was significantly increased in the case of those hospitals above 250. A more detailed and thorough investigation is needed for verifying factors influencing physician's productivity in general hospitals in Korea.